<?xml version="1.0" encoding="ascii"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
          "DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <title>chimera.core.rwlock</title>
  <link rel="stylesheet" href="epydoc.css" type="text/css" />
  <script type="text/javascript" src="epydoc.js"></script>
</head>

<body bgcolor="white" text="black" link="blue" vlink="#204080"
      alink="#204080">
<!-- ==================== NAVIGATION BAR ==================== -->
<table class="navbar" border="0" width="100%" cellpadding="0"
       bgcolor="#a0c0ff" cellspacing="0">
  <tr valign="middle">
  <!-- Home link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="chimera-module.html">Home</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Tree link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="module-tree.html">Trees</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Index link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="identifier-index.html">Indices</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Help link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="help.html">Help</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Project homepage -->
      <th class="navbar" align="right" width="100%">
        <table border="0" cellpadding="0" cellspacing="0">
          <tr><th class="navbar" align="center"
            ><a class="navbar" target="_top" href="http://chimera.ufsc.br/">Chimera - Observatoty Automation System</a></th>
          </tr></table></th>
  </tr>
</table>
<table width="100%" cellpadding="0" cellspacing="0">
  <tr valign="top">
    <td width="100%">
      <span class="breadcrumbs">
        <a href="chimera-module.html">Package&nbsp;chimera</a> ::
        <a href="chimera.core-module.html">Package&nbsp;core</a> ::
        Module&nbsp;rwlock
      </span>
    </td>
    <td>
      <table cellpadding="0" cellspacing="0">
        <!-- hide/show private -->
        <tr><td align="right"><span class="options">[<a href="javascript:void(0);" class="privatelink"
    onclick="toggle_private();">hide&nbsp;private</a>]</span></td></tr>
        <tr><td align="right"><span class="options"
            >[<a href="frames.html" target="_top">frames</a
            >]&nbsp;|&nbsp;<a href="chimera.core.rwlock-pysrc.html"
            target="_top">no&nbsp;frames</a>]</span></td></tr>
      </table>
    </td>
  </tr>
</table>
<h1 class="epydoc">Source Code for <a href="chimera.core.rwlock-module.html">Module chimera.core.rwlock</a></h1>
<pre class="py-src">
<a name="L1"></a><tt class="py-lineno">  1</tt>  <tt class="py-line"><tt class="py-comment"># -*- coding: iso-8859-15 -*-</tt> </tt>
<a name="L2"></a><tt class="py-lineno">  2</tt>  <tt class="py-line"><tt class="py-comment"></tt><tt class="py-docstring">"""locks.py - Read-Write lock thread lock implementation</tt> </tt>
<a name="L3"></a><tt class="py-lineno">  3</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L4"></a><tt class="py-lineno">  4</tt>  <tt class="py-line"><tt class="py-docstring">See the class documentation for more info.</tt> </tt>
<a name="L5"></a><tt class="py-lineno">  5</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L6"></a><tt class="py-lineno">  6</tt>  <tt class="py-line"><tt class="py-docstring">Copyright (C) 2007, Heiko Wundram.</tt> </tt>
<a name="L7"></a><tt class="py-lineno">  7</tt>  <tt class="py-line"><tt class="py-docstring">Released under the BSD-license.</tt> </tt>
<a name="L8"></a><tt class="py-lineno">  8</tt>  <tt class="py-line"><tt class="py-docstring">"""</tt> </tt>
<a name="L9"></a><tt class="py-lineno">  9</tt>  <tt class="py-line"> </tt>
<a name="L10"></a><tt class="py-lineno"> 10</tt>  <tt class="py-line"><tt class="py-comment"># Imports</tt> </tt>
<a name="L11"></a><tt class="py-lineno"> 11</tt>  <tt class="py-line"><tt class="py-comment"></tt><tt class="py-comment"># -------</tt> </tt>
<a name="L12"></a><tt class="py-lineno"> 12</tt>  <tt class="py-line"><tt class="py-comment"></tt> </tt>
<a name="L13"></a><tt class="py-lineno"> 13</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">threading</tt> <tt class="py-keyword">import</tt> <tt class="py-name">Condition</tt><tt class="py-op">,</tt> <tt class="py-name">Lock</tt><tt class="py-op">,</tt> <tt class="py-name">currentThread</tt> </tt>
<a name="L14"></a><tt class="py-lineno"> 14</tt>  <tt class="py-line"><tt class="py-keyword">from</tt> <tt class="py-name">time</tt> <tt class="py-keyword">import</tt> <tt class="py-name">time</tt> </tt>
<a name="L15"></a><tt class="py-lineno"> 15</tt>  <tt class="py-line"> </tt>
<a name="L16"></a><tt class="py-lineno"> 16</tt>  <tt class="py-line"> </tt>
<a name="L17"></a><tt class="py-lineno"> 17</tt>  <tt class="py-line"><tt class="py-comment"># Read write lock</tt> </tt>
<a name="L18"></a><tt class="py-lineno"> 18</tt>  <tt class="py-line"><tt class="py-comment"></tt><tt class="py-comment"># ---------------</tt> </tt>
<a name="L19"></a><tt class="py-lineno"> 19</tt>  <tt class="py-line"><tt class="py-comment"></tt> </tt>
<a name="ReadWriteLock"></a><div id="ReadWriteLock-def"><a name="L20"></a><tt class="py-lineno"> 20</tt> <a class="py-toggle" href="#" id="ReadWriteLock-toggle" onclick="return toggle('ReadWriteLock');">-</a><tt class="py-line"><tt class="py-keyword">class</tt> <a class="py-def-name" href="chimera.core.rwlock.ReadWriteLock-class.html">ReadWriteLock</a><tt class="py-op">(</tt><tt class="py-base-class">object</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="ReadWriteLock-collapsed" style="display:none;" pad="+++" indent="++++"></div><div id="ReadWriteLock-expanded"><a name="L21"></a><tt class="py-lineno"> 21</tt>  <tt class="py-line">    <tt class="py-docstring">"""Read-Write lock class. A read-write lock differs from a standard</tt> </tt>
<a name="L22"></a><tt class="py-lineno"> 22</tt>  <tt class="py-line"><tt class="py-docstring">    threading.RLock() by allowing multiple threads to simultaneously hold a</tt> </tt>
<a name="L23"></a><tt class="py-lineno"> 23</tt>  <tt class="py-line"><tt class="py-docstring">    read lock, while allowing only a single thread to hold a write lock at the</tt> </tt>
<a name="L24"></a><tt class="py-lineno"> 24</tt>  <tt class="py-line"><tt class="py-docstring">    same point of time.</tt> </tt>
<a name="L25"></a><tt class="py-lineno"> 25</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L26"></a><tt class="py-lineno"> 26</tt>  <tt class="py-line"><tt class="py-docstring">    When a read lock is requested while a write lock is held, the reader</tt> </tt>
<a name="L27"></a><tt class="py-lineno"> 27</tt>  <tt class="py-line"><tt class="py-docstring">    is blocked; when a write lock is requested while another write lock is</tt> </tt>
<a name="L28"></a><tt class="py-lineno"> 28</tt>  <tt class="py-line"><tt class="py-docstring">    held or there are read locks, the writer is blocked.</tt> </tt>
<a name="L29"></a><tt class="py-lineno"> 29</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L30"></a><tt class="py-lineno"> 30</tt>  <tt class="py-line"><tt class="py-docstring">    Writers are always preferred by this implementation: if there are blocked</tt> </tt>
<a name="L31"></a><tt class="py-lineno"> 31</tt>  <tt class="py-line"><tt class="py-docstring">    threads waiting for a write lock, current readers may request more read</tt> </tt>
<a name="L32"></a><tt class="py-lineno"> 32</tt>  <tt class="py-line"><tt class="py-docstring">    locks (which they eventually should free, as they starve the waiting</tt> </tt>
<a name="L33"></a><tt class="py-lineno"> 33</tt>  <tt class="py-line"><tt class="py-docstring">    writers otherwise), but a new thread requesting a read lock will not</tt> </tt>
<a name="L34"></a><tt class="py-lineno"> 34</tt>  <tt class="py-line"><tt class="py-docstring">    be granted one, and block. This might mean starvation for readers if</tt> </tt>
<a name="L35"></a><tt class="py-lineno"> 35</tt>  <tt class="py-line"><tt class="py-docstring">    two writer threads interweave their calls to acquireWrite() without</tt> </tt>
<a name="L36"></a><tt class="py-lineno"> 36</tt>  <tt class="py-line"><tt class="py-docstring">    leaving a window only for readers.</tt> </tt>
<a name="L37"></a><tt class="py-lineno"> 37</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L38"></a><tt class="py-lineno"> 38</tt>  <tt class="py-line"><tt class="py-docstring">    In case a current reader requests a write lock, this can and will be</tt> </tt>
<a name="L39"></a><tt class="py-lineno"> 39</tt>  <tt class="py-line"><tt class="py-docstring">    satisfied without giving up the read locks first, but, only one thread</tt> </tt>
<a name="L40"></a><tt class="py-lineno"> 40</tt>  <tt class="py-line"><tt class="py-docstring">    may perform this kind of lock upgrade, as a deadlock would otherwise</tt> </tt>
<a name="L41"></a><tt class="py-lineno"> 41</tt>  <tt class="py-line"><tt class="py-docstring">    occur. After the write lock has been granted, the thread will hold a</tt> </tt>
<a name="L42"></a><tt class="py-lineno"> 42</tt>  <tt class="py-line"><tt class="py-docstring">    full write lock, and not be downgraded after the upgrading call to</tt> </tt>
<a name="L43"></a><tt class="py-lineno"> 43</tt>  <tt class="py-line"><tt class="py-docstring">    acquireWrite() has been match by a corresponding release().</tt> </tt>
<a name="L44"></a><tt class="py-lineno"> 44</tt>  <tt class="py-line"><tt class="py-docstring">    """</tt> </tt>
<a name="L45"></a><tt class="py-lineno"> 45</tt>  <tt class="py-line"> </tt>
<a name="ReadWriteLock.__init__"></a><div id="ReadWriteLock.__init__-def"><a name="L46"></a><tt class="py-lineno"> 46</tt> <a class="py-toggle" href="#" id="ReadWriteLock.__init__-toggle" onclick="return toggle('ReadWriteLock.__init__');">-</a><tt class="py-line">    <tt class="py-keyword">def</tt> <a class="py-def-name" href="chimera.core.rwlock.ReadWriteLock-class.html#__init__">__init__</a><tt class="py-op">(</tt><tt class="py-param">self</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="ReadWriteLock.__init__-collapsed" style="display:none;" pad="+++" indent="++++++++"></div><div id="ReadWriteLock.__init__-expanded"><a name="L47"></a><tt class="py-lineno"> 47</tt>  <tt class="py-line">        <tt class="py-docstring">"""Initialize this read-write lock."""</tt> </tt>
<a name="L48"></a><tt class="py-lineno"> 48</tt>  <tt class="py-line"> </tt>
<a name="L49"></a><tt class="py-lineno"> 49</tt>  <tt class="py-line">        <tt class="py-comment"># Condition variable, used to signal waiters of a change in object</tt> </tt>
<a name="L50"></a><tt class="py-lineno"> 50</tt>  <tt class="py-line"><tt class="py-comment"></tt>        <tt class="py-comment"># state.</tt> </tt>
<a name="L51"></a><tt class="py-lineno"> 51</tt>  <tt class="py-line"><tt class="py-comment"></tt>        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt> <tt class="py-op">=</tt> <tt class="py-name">Condition</tt><tt class="py-op">(</tt><tt class="py-name">Lock</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">)</tt> </tt>
<a name="L52"></a><tt class="py-lineno"> 52</tt>  <tt class="py-line"> </tt>
<a name="L53"></a><tt class="py-lineno"> 53</tt>  <tt class="py-line">        <tt class="py-comment"># Initialize with no writers.</tt> </tt>
<a name="L54"></a><tt class="py-lineno"> 54</tt>  <tt class="py-line"><tt class="py-comment"></tt>        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-op">=</tt> <tt class="py-name">None</tt> </tt>
<a name="L55"></a><tt class="py-lineno"> 55</tt>  <tt class="py-line">        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-op">=</tt> <tt class="py-number">0</tt> </tt>
<a name="L56"></a><tt class="py-lineno"> 56</tt>  <tt class="py-line">        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt> <tt class="py-op">=</tt> <tt class="py-op">[</tt><tt class="py-op">]</tt> </tt>
<a name="L57"></a><tt class="py-lineno"> 57</tt>  <tt class="py-line"> </tt>
<a name="L58"></a><tt class="py-lineno"> 58</tt>  <tt class="py-line">        <tt class="py-comment"># Initialize with no readers.</tt> </tt>
<a name="L59"></a><tt class="py-lineno"> 59</tt>  <tt class="py-line"><tt class="py-comment"></tt>        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt> <tt class="py-op">=</tt> <tt class="py-op">{</tt><tt class="py-op">}</tt> </tt>
</div><a name="L60"></a><tt class="py-lineno"> 60</tt>  <tt class="py-line"> </tt>
<a name="ReadWriteLock.acquireRead"></a><div id="ReadWriteLock.acquireRead-def"><a name="L61"></a><tt class="py-lineno"> 61</tt> <a class="py-toggle" href="#" id="ReadWriteLock.acquireRead-toggle" onclick="return toggle('ReadWriteLock.acquireRead');">-</a><tt class="py-line">    <tt class="py-keyword">def</tt> <a class="py-def-name" href="chimera.core.rwlock.ReadWriteLock-class.html#acquireRead">acquireRead</a><tt class="py-op">(</tt><tt class="py-param">self</tt><tt class="py-op">,</tt><tt class="py-param">timeout</tt><tt class="py-op">=</tt><tt class="py-name">None</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="ReadWriteLock.acquireRead-collapsed" style="display:none;" pad="+++" indent="++++++++"></div><div id="ReadWriteLock.acquireRead-expanded"><a name="L62"></a><tt class="py-lineno"> 62</tt>  <tt class="py-line">        <tt class="py-docstring">"""Acquire a read lock for the current thread, waiting at most</tt> </tt>
<a name="L63"></a><tt class="py-lineno"> 63</tt>  <tt class="py-line"><tt class="py-docstring">        timeout seconds or doing a non-blocking check in case timeout is &lt;= 0.</tt> </tt>
<a name="L64"></a><tt class="py-lineno"> 64</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L65"></a><tt class="py-lineno"> 65</tt>  <tt class="py-line"><tt class="py-docstring">        In case timeout is None, the call to acquireRead blocks until the</tt> </tt>
<a name="L66"></a><tt class="py-lineno"> 66</tt>  <tt class="py-line"><tt class="py-docstring">        lock request can be serviced.</tt> </tt>
<a name="L67"></a><tt class="py-lineno"> 67</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L68"></a><tt class="py-lineno"> 68</tt>  <tt class="py-line"><tt class="py-docstring">        In case the timeout expires before the lock could be serviced, a</tt> </tt>
<a name="L69"></a><tt class="py-lineno"> 69</tt>  <tt class="py-line"><tt class="py-docstring">        RuntimeError is thrown."""</tt> </tt>
<a name="L70"></a><tt class="py-lineno"> 70</tt>  <tt class="py-line"> </tt>
<a name="L71"></a><tt class="py-lineno"> 71</tt>  <tt class="py-line">        <tt class="py-keyword">if</tt> <tt class="py-name">timeout</tt> <tt class="py-keyword">is</tt> <tt class="py-keyword">not</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L72"></a><tt class="py-lineno"> 72</tt>  <tt class="py-line">            <tt class="py-name">endtime</tt> <tt class="py-op">=</tt> <tt class="py-name">time</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> <tt class="py-op">+</tt> <tt class="py-name">timeout</tt> </tt>
<a name="L73"></a><tt class="py-lineno"> 73</tt>  <tt class="py-line">        <tt class="py-name">me</tt> <tt class="py-op">=</tt> <tt class="py-name">currentThread</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L74"></a><tt class="py-lineno"> 74</tt>  <tt class="py-line">        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-0" class="py-name" targets="Method chimera.core.chimeraobject.ChimeraObject.acquire()=chimera.core.chimeraobject.ChimeraObject-class.html#acquire"><a title="chimera.core.chimeraobject.ChimeraObject.acquire" class="py-name" href="#" onclick="return doclink('link-0', 'acquire', 'link-0');">acquire</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L75"></a><tt class="py-lineno"> 75</tt>  <tt class="py-line">        <tt class="py-keyword">try</tt><tt class="py-op">:</tt> </tt>
<a name="L76"></a><tt class="py-lineno"> 76</tt>  <tt class="py-line">            <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-keyword">is</tt> <tt class="py-name">me</tt><tt class="py-op">:</tt> </tt>
<a name="L77"></a><tt class="py-lineno"> 77</tt>  <tt class="py-line">                <tt class="py-comment"># If we are the writer, grant a new read lock, always.</tt> </tt>
<a name="L78"></a><tt class="py-lineno"> 78</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt> <tt class="py-op">+=</tt> <tt class="py-number">1</tt> </tt>
<a name="L79"></a><tt class="py-lineno"> 79</tt>  <tt class="py-line">                <tt class="py-keyword">return</tt> </tt>
<a name="L80"></a><tt class="py-lineno"> 80</tt>  <tt class="py-line">            <tt class="py-keyword">while</tt> <tt id="link-1" class="py-name" targets="Variable chimera.core.threads.True=chimera.core.threads-module.html#True"><a title="chimera.core.threads.True" class="py-name" href="#" onclick="return doclink('link-1', 'True', 'link-1');">True</a></tt><tt class="py-op">:</tt> </tt>
<a name="L81"></a><tt class="py-lineno"> 81</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-keyword">is</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L82"></a><tt class="py-lineno"> 82</tt>  <tt class="py-line">                    <tt class="py-comment"># Only test anything if there is no current writer.</tt> </tt>
<a name="L83"></a><tt class="py-lineno"> 83</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-keyword">or</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt><tt class="py-op">:</tt> </tt>
<a name="L84"></a><tt class="py-lineno"> 84</tt>  <tt class="py-line">                        <tt class="py-keyword">if</tt> <tt class="py-name">me</tt> <tt class="py-keyword">in</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">:</tt> </tt>
<a name="L85"></a><tt class="py-lineno"> 85</tt>  <tt class="py-line">                            <tt class="py-comment"># Only grant a read lock if we already have one</tt> </tt>
<a name="L86"></a><tt class="py-lineno"> 86</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># in case writers are waiting for their turn.</tt> </tt>
<a name="L87"></a><tt class="py-lineno"> 87</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># This means that writers can't easily get starved</tt> </tt>
<a name="L88"></a><tt class="py-lineno"> 88</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># (but see below, readers can).</tt> </tt>
<a name="L89"></a><tt class="py-lineno"> 89</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt> <tt class="py-op">+=</tt> <tt class="py-number">1</tt> </tt>
<a name="L90"></a><tt class="py-lineno"> 90</tt>  <tt class="py-line">                            <tt class="py-keyword">return</tt> </tt>
<a name="L91"></a><tt class="py-lineno"> 91</tt>  <tt class="py-line">                        <tt class="py-comment"># No, we aren't a reader (yet), wait for our turn.</tt> </tt>
<a name="L92"></a><tt class="py-lineno"> 92</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L93"></a><tt class="py-lineno"> 93</tt>  <tt class="py-line">                        <tt class="py-comment"># Grant a new read lock, always, in case there are</tt> </tt>
<a name="L94"></a><tt class="py-lineno"> 94</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># no pending writers (and no writer).</tt> </tt>
<a name="L95"></a><tt class="py-lineno"> 95</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt> <tt class="py-op">=</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">.</tt><tt id="link-2" class="py-name" targets="Method chimera.core.config.Option.get()=chimera.core.config.Option-class.html#get,Method chimera.core.resources.ResourcesManager.get()=chimera.core.resources.ResourcesManager-class.html#get,Method chimera.util.coord.Coord.get()=chimera.util.coord.Coord-class.html#get,Method chimera.util.ds9.DS9.get()=chimera.util.ds9.DS9-class.html#get,Method chimera.util.etree.ElementTree._ElementInterface.get()=chimera.util.etree.ElementTree._ElementInterface-class.html#get"><a title="chimera.core.config.Option.get
chimera.core.resources.ResourcesManager.get
chimera.util.coord.Coord.get
chimera.util.ds9.DS9.get
chimera.util.etree.ElementTree._ElementInterface.get" class="py-name" href="#" onclick="return doclink('link-2', 'get', 'link-2');">get</a></tt><tt class="py-op">(</tt><tt class="py-name">me</tt><tt class="py-op">,</tt><tt class="py-number">0</tt><tt class="py-op">)</tt> <tt class="py-op">+</tt> <tt class="py-number">1</tt> </tt>
<a name="L96"></a><tt class="py-lineno"> 96</tt>  <tt class="py-line">                        <tt class="py-keyword">return</tt> </tt>
<a name="L97"></a><tt class="py-lineno"> 97</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-name">timeout</tt> <tt class="py-keyword">is</tt> <tt class="py-keyword">not</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L98"></a><tt class="py-lineno"> 98</tt>  <tt class="py-line">                    <tt class="py-name">remaining</tt> <tt class="py-op">=</tt> <tt class="py-name">endtime</tt> <tt class="py-op">-</tt> <tt class="py-name">time</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L99"></a><tt class="py-lineno"> 99</tt>  <tt class="py-line">                    <tt class="py-keyword">if</tt> <tt class="py-name">remaining</tt> <tt class="py-op">&lt;=</tt> <tt class="py-number">0</tt><tt class="py-op">:</tt> </tt>
<a name="L100"></a><tt class="py-lineno">100</tt>  <tt class="py-line">                        <tt class="py-comment"># Timeout has expired, signal caller of this.</tt> </tt>
<a name="L101"></a><tt class="py-lineno">101</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-keyword">raise</tt> <tt class="py-name">RuntimeError</tt><tt class="py-op">(</tt><tt class="py-string">"Acquiring read lock timed out"</tt><tt class="py-op">)</tt> </tt>
<a name="L102"></a><tt class="py-lineno">102</tt>  <tt class="py-line">                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-3" class="py-name" targets="Method chimera.core.chimeraobject.ChimeraObject.wait()=chimera.core.chimeraobject.ChimeraObject-class.html#wait,Method chimera.core.manager.Manager.wait()=chimera.core.manager.Manager-class.html#wait"><a title="chimera.core.chimeraobject.ChimeraObject.wait
chimera.core.manager.Manager.wait" class="py-name" href="#" onclick="return doclink('link-3', 'wait', 'link-3');">wait</a></tt><tt class="py-op">(</tt><tt class="py-name">remaining</tt><tt class="py-op">)</tt> </tt>
<a name="L103"></a><tt class="py-lineno">103</tt>  <tt class="py-line">                <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L104"></a><tt class="py-lineno">104</tt>  <tt class="py-line">                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-4" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.wait
chimera.core.manager.Manager.wait" class="py-name" href="#" onclick="return doclink('link-4', 'wait', 'link-3');">wait</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L105"></a><tt class="py-lineno">105</tt>  <tt class="py-line">        <tt class="py-keyword">finally</tt><tt class="py-op">:</tt> </tt>
<a name="L106"></a><tt class="py-lineno">106</tt>  <tt class="py-line">            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-5" class="py-name" targets="Method chimera.core.chimeraobject.ChimeraObject.release()=chimera.core.chimeraobject.ChimeraObject-class.html#release,Method chimera.core.rwlock.ReadWriteLock.release()=chimera.core.rwlock.ReadWriteLock-class.html#release"><a title="chimera.core.chimeraobject.ChimeraObject.release
chimera.core.rwlock.ReadWriteLock.release" class="py-name" href="#" onclick="return doclink('link-5', 'release', 'link-5');">release</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
</div><a name="L107"></a><tt class="py-lineno">107</tt>  <tt class="py-line"> </tt>
<a name="ReadWriteLock.acquireWrite"></a><div id="ReadWriteLock.acquireWrite-def"><a name="L108"></a><tt class="py-lineno">108</tt> <a class="py-toggle" href="#" id="ReadWriteLock.acquireWrite-toggle" onclick="return toggle('ReadWriteLock.acquireWrite');">-</a><tt class="py-line">    <tt class="py-keyword">def</tt> <a class="py-def-name" href="chimera.core.rwlock.ReadWriteLock-class.html#acquireWrite">acquireWrite</a><tt class="py-op">(</tt><tt class="py-param">self</tt><tt class="py-op">,</tt><tt class="py-param">timeout</tt><tt class="py-op">=</tt><tt class="py-name">None</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="ReadWriteLock.acquireWrite-collapsed" style="display:none;" pad="+++" indent="++++++++"></div><div id="ReadWriteLock.acquireWrite-expanded"><a name="L109"></a><tt class="py-lineno">109</tt>  <tt class="py-line">        <tt class="py-docstring">"""Acquire a write lock for the current thread, waiting at most</tt> </tt>
<a name="L110"></a><tt class="py-lineno">110</tt>  <tt class="py-line"><tt class="py-docstring">        timeout seconds or doing a non-blocking check in case timeout is &lt;= 0.</tt> </tt>
<a name="L111"></a><tt class="py-lineno">111</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L112"></a><tt class="py-lineno">112</tt>  <tt class="py-line"><tt class="py-docstring">        In case the write lock cannot be serviced due to the deadlock</tt> </tt>
<a name="L113"></a><tt class="py-lineno">113</tt>  <tt class="py-line"><tt class="py-docstring">        condition mentioned above, a ValueError is raised.</tt> </tt>
<a name="L114"></a><tt class="py-lineno">114</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L115"></a><tt class="py-lineno">115</tt>  <tt class="py-line"><tt class="py-docstring">        In case timeout is None, the call to acquireWrite blocks until the</tt> </tt>
<a name="L116"></a><tt class="py-lineno">116</tt>  <tt class="py-line"><tt class="py-docstring">        lock request can be serviced.</tt> </tt>
<a name="L117"></a><tt class="py-lineno">117</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L118"></a><tt class="py-lineno">118</tt>  <tt class="py-line"><tt class="py-docstring">        In case the timeout expires before the lock could be serviced, a</tt> </tt>
<a name="L119"></a><tt class="py-lineno">119</tt>  <tt class="py-line"><tt class="py-docstring">        RuntimeError is thrown."""</tt> </tt>
<a name="L120"></a><tt class="py-lineno">120</tt>  <tt class="py-line"> </tt>
<a name="L121"></a><tt class="py-lineno">121</tt>  <tt class="py-line">        <tt class="py-keyword">if</tt> <tt class="py-name">timeout</tt> <tt class="py-keyword">is</tt> <tt class="py-keyword">not</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L122"></a><tt class="py-lineno">122</tt>  <tt class="py-line">            <tt class="py-name">endtime</tt> <tt class="py-op">=</tt> <tt class="py-name">time</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> <tt class="py-op">+</tt> <tt class="py-name">timeout</tt> </tt>
<a name="L123"></a><tt class="py-lineno">123</tt>  <tt class="py-line">        <tt class="py-name">me</tt><tt class="py-op">,</tt> <tt class="py-name">upgradewriter</tt> <tt class="py-op">=</tt> <tt class="py-name">currentThread</tt><tt class="py-op">(</tt><tt class="py-op">)</tt><tt class="py-op">,</tt> <tt id="link-6" class="py-name" targets="Variable chimera.core.threads.False=chimera.core.threads-module.html#False"><a title="chimera.core.threads.False" class="py-name" href="#" onclick="return doclink('link-6', 'False', 'link-6');">False</a></tt> </tt>
<a name="L124"></a><tt class="py-lineno">124</tt>  <tt class="py-line">        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-7" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.acquire" class="py-name" href="#" onclick="return doclink('link-7', 'acquire', 'link-0');">acquire</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L125"></a><tt class="py-lineno">125</tt>  <tt class="py-line">        <tt class="py-keyword">try</tt><tt class="py-op">:</tt> </tt>
<a name="L126"></a><tt class="py-lineno">126</tt>  <tt class="py-line">            <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-keyword">is</tt> <tt class="py-name">me</tt><tt class="py-op">:</tt> </tt>
<a name="L127"></a><tt class="py-lineno">127</tt>  <tt class="py-line">                <tt class="py-comment"># If we are the writer, grant a new write lock, always.</tt> </tt>
<a name="L128"></a><tt class="py-lineno">128</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt> <tt class="py-op">+=</tt> <tt class="py-number">1</tt> </tt>
<a name="L129"></a><tt class="py-lineno">129</tt>  <tt class="py-line">                <tt class="py-keyword">return</tt> </tt>
<a name="L130"></a><tt class="py-lineno">130</tt>  <tt class="py-line">            <tt class="py-keyword">elif</tt> <tt class="py-name">me</tt> <tt class="py-keyword">in</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">:</tt> </tt>
<a name="L131"></a><tt class="py-lineno">131</tt>  <tt class="py-line">                <tt class="py-comment"># If we are a reader, no need to add us to pendingwriters,</tt> </tt>
<a name="L132"></a><tt class="py-lineno">132</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-comment"># we get the upgradewriter slot.</tt> </tt>
<a name="L133"></a><tt class="py-lineno">133</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt><tt class="py-op">:</tt> </tt>
<a name="L134"></a><tt class="py-lineno">134</tt>  <tt class="py-line">                    <tt class="py-comment"># If we are a reader and want to upgrade, and someone</tt> </tt>
<a name="L135"></a><tt class="py-lineno">135</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-comment"># else also wants to upgrade, there is no way we can do</tt> </tt>
<a name="L136"></a><tt class="py-lineno">136</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-comment"># this except if one of us releases all his read locks.</tt> </tt>
<a name="L137"></a><tt class="py-lineno">137</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-comment"># Signal this to user.</tt> </tt>
<a name="L138"></a><tt class="py-lineno">138</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">raise</tt> <tt class="py-name">ValueError</tt><tt class="py-op">(</tt> </tt>
<a name="L139"></a><tt class="py-lineno">139</tt>  <tt class="py-line">                        <tt class="py-string">"Inevitable dead lock, denying write lock"</tt> </tt>
<a name="L140"></a><tt class="py-lineno">140</tt>  <tt class="py-line">                        <tt class="py-op">)</tt> </tt>
<a name="L141"></a><tt class="py-lineno">141</tt>  <tt class="py-line">                <tt class="py-name">upgradewriter</tt> <tt class="py-op">=</tt> <tt id="link-8" class="py-name"><a title="chimera.core.threads.True" class="py-name" href="#" onclick="return doclink('link-8', 'True', 'link-1');">True</a></tt> </tt>
<a name="L142"></a><tt class="py-lineno">142</tt>  <tt class="py-line">                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-op">=</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">.</tt><tt class="py-name">pop</tt><tt class="py-op">(</tt><tt class="py-name">me</tt><tt class="py-op">)</tt> </tt>
<a name="L143"></a><tt class="py-lineno">143</tt>  <tt class="py-line">            <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L144"></a><tt class="py-lineno">144</tt>  <tt class="py-line">                <tt class="py-comment"># We aren't a reader, so add us to the pending writers queue</tt> </tt>
<a name="L145"></a><tt class="py-lineno">145</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-comment"># for synchronization with the readers.</tt> </tt>
<a name="L146"></a><tt class="py-lineno">146</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt><tt class="py-op">.</tt><tt id="link-9" class="py-name" targets="Method chimera.util.etree.ElementTree._ElementInterface.append()=chimera.util.etree.ElementTree._ElementInterface-class.html#append,Method chimera.util.votable.VOTable.append()=chimera.util.votable.VOTable-class.html#append"><a title="chimera.util.etree.ElementTree._ElementInterface.append
chimera.util.votable.VOTable.append" class="py-name" href="#" onclick="return doclink('link-9', 'append', 'link-9');">append</a></tt><tt class="py-op">(</tt><tt class="py-name">me</tt><tt class="py-op">)</tt> </tt>
<a name="L147"></a><tt class="py-lineno">147</tt>  <tt class="py-line">            <tt class="py-keyword">while</tt> <tt id="link-10" class="py-name"><a title="chimera.core.threads.True" class="py-name" href="#" onclick="return doclink('link-10', 'True', 'link-1');">True</a></tt><tt class="py-op">:</tt> </tt>
<a name="L148"></a><tt class="py-lineno">148</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-keyword">not</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt> <tt class="py-keyword">and</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-keyword">is</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L149"></a><tt class="py-lineno">149</tt>  <tt class="py-line">                    <tt class="py-comment"># Only test anything if there are no readers and writers.</tt> </tt>
<a name="L150"></a><tt class="py-lineno">150</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt><tt class="py-op">:</tt> </tt>
<a name="L151"></a><tt class="py-lineno">151</tt>  <tt class="py-line">                        <tt class="py-keyword">if</tt> <tt class="py-name">upgradewriter</tt><tt class="py-op">:</tt> </tt>
<a name="L152"></a><tt class="py-lineno">152</tt>  <tt class="py-line">                            <tt class="py-comment"># There is a writer to upgrade, and it's us. Take</tt> </tt>
<a name="L153"></a><tt class="py-lineno">153</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># the write lock.</tt> </tt>
<a name="L154"></a><tt class="py-lineno">154</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-op">=</tt> <tt class="py-name">me</tt> </tt>
<a name="L155"></a><tt class="py-lineno">155</tt>  <tt class="py-line">                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt> <tt class="py-op">=</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-op">+</tt> <tt class="py-number">1</tt> </tt>
<a name="L156"></a><tt class="py-lineno">156</tt>  <tt class="py-line">                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-op">=</tt> <tt class="py-number">0</tt> </tt>
<a name="L157"></a><tt class="py-lineno">157</tt>  <tt class="py-line">                            <tt class="py-keyword">return</tt> </tt>
<a name="L158"></a><tt class="py-lineno">158</tt>  <tt class="py-line">                        <tt class="py-comment"># There is a writer to upgrade, but it's not us.</tt> </tt>
<a name="L159"></a><tt class="py-lineno">159</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># Always leave the upgrade writer the advance slot,</tt> </tt>
<a name="L160"></a><tt class="py-lineno">160</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># because he presumes he'll get a write lock directly</tt> </tt>
<a name="L161"></a><tt class="py-lineno">161</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># from a previously held read lock.</tt> </tt>
<a name="L162"></a><tt class="py-lineno">162</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">elif</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt><tt class="py-op">[</tt><tt class="py-number">0</tt><tt class="py-op">]</tt> <tt class="py-keyword">is</tt> <tt class="py-name">me</tt><tt class="py-op">:</tt> </tt>
<a name="L163"></a><tt class="py-lineno">163</tt>  <tt class="py-line">                        <tt class="py-comment"># If there are no readers and writers, it's always</tt> </tt>
<a name="L164"></a><tt class="py-lineno">164</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># fine for us to take the writer slot, removing us</tt> </tt>
<a name="L165"></a><tt class="py-lineno">165</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># from the pending writers queue.</tt> </tt>
<a name="L166"></a><tt class="py-lineno">166</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># This might mean starvation for readers, though.</tt> </tt>
<a name="L167"></a><tt class="py-lineno">167</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-op">=</tt> <tt class="py-name">me</tt> </tt>
<a name="L168"></a><tt class="py-lineno">168</tt>  <tt class="py-line">                        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt> <tt class="py-op">=</tt> <tt class="py-number">1</tt> </tt>
<a name="L169"></a><tt class="py-lineno">169</tt>  <tt class="py-line">                        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt> <tt class="py-op">=</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt><tt class="py-op">[</tt><tt class="py-number">1</tt><tt class="py-op">:</tt><tt class="py-op">]</tt> </tt>
<a name="L170"></a><tt class="py-lineno">170</tt>  <tt class="py-line">                        <tt class="py-keyword">return</tt> </tt>
<a name="L171"></a><tt class="py-lineno">171</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-name">timeout</tt> <tt class="py-keyword">is</tt> <tt class="py-keyword">not</tt> <tt class="py-name">None</tt><tt class="py-op">:</tt> </tt>
<a name="L172"></a><tt class="py-lineno">172</tt>  <tt class="py-line">                    <tt class="py-name">remaining</tt> <tt class="py-op">=</tt> <tt class="py-name">endtime</tt> <tt class="py-op">-</tt> <tt class="py-name">time</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L173"></a><tt class="py-lineno">173</tt>  <tt class="py-line">                    <tt class="py-keyword">if</tt> <tt class="py-name">remaining</tt> <tt class="py-op">&lt;=</tt> <tt class="py-number">0</tt><tt class="py-op">:</tt> </tt>
<a name="L174"></a><tt class="py-lineno">174</tt>  <tt class="py-line">                        <tt class="py-comment"># Timeout has expired, signal caller of this.</tt> </tt>
<a name="L175"></a><tt class="py-lineno">175</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-keyword">if</tt> <tt class="py-name">upgradewriter</tt><tt class="py-op">:</tt> </tt>
<a name="L176"></a><tt class="py-lineno">176</tt>  <tt class="py-line">                            <tt class="py-comment"># Put us back on the reader queue. No need to</tt> </tt>
<a name="L177"></a><tt class="py-lineno">177</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># signal anyone of this change, because no other</tt> </tt>
<a name="L178"></a><tt class="py-lineno">178</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># writer could've taken our spot before we got</tt> </tt>
<a name="L179"></a><tt class="py-lineno">179</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># here (because of remaining readers), as the test</tt> </tt>
<a name="L180"></a><tt class="py-lineno">180</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># for proper conditions is at the start of the</tt> </tt>
<a name="L181"></a><tt class="py-lineno">181</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># loop, not at the end.</tt> </tt>
<a name="L182"></a><tt class="py-lineno">182</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt> <tt class="py-op">=</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> </tt>
<a name="L183"></a><tt class="py-lineno">183</tt>  <tt class="py-line">                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__upgradewritercount</tt> <tt class="py-op">=</tt> <tt class="py-number">0</tt> </tt>
<a name="L184"></a><tt class="py-lineno">184</tt>  <tt class="py-line">                        <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L185"></a><tt class="py-lineno">185</tt>  <tt class="py-line">                            <tt class="py-comment"># We were a simple pending writer, just remove us</tt> </tt>
<a name="L186"></a><tt class="py-lineno">186</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-comment"># from the FIFO list.</tt> </tt>
<a name="L187"></a><tt class="py-lineno">187</tt>  <tt class="py-line"><tt class="py-comment"></tt>                            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__pendingwriters</tt><tt class="py-op">.</tt><tt id="link-11" class="py-name" targets="Method chimera.core.manager.Manager.remove()=chimera.core.manager.Manager-class.html#remove,Method chimera.core.resources.ResourcesManager.remove()=chimera.core.resources.ResourcesManager-class.html#remove,Method chimera.util.etree.ElementTree._ElementInterface.remove()=chimera.util.etree.ElementTree._ElementInterface-class.html#remove"><a title="chimera.core.manager.Manager.remove
chimera.core.resources.ResourcesManager.remove
chimera.util.etree.ElementTree._ElementInterface.remove" class="py-name" href="#" onclick="return doclink('link-11', 'remove', 'link-11');">remove</a></tt><tt class="py-op">(</tt><tt class="py-name">me</tt><tt class="py-op">)</tt> </tt>
<a name="L188"></a><tt class="py-lineno">188</tt>  <tt class="py-line">                        <tt class="py-keyword">raise</tt> <tt class="py-name">RuntimeError</tt><tt class="py-op">(</tt><tt class="py-string">"Acquiring write lock timed out"</tt><tt class="py-op">)</tt> </tt>
<a name="L189"></a><tt class="py-lineno">189</tt>  <tt class="py-line">                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-12" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.wait
chimera.core.manager.Manager.wait" class="py-name" href="#" onclick="return doclink('link-12', 'wait', 'link-3');">wait</a></tt><tt class="py-op">(</tt><tt class="py-name">remaining</tt><tt class="py-op">)</tt> </tt>
<a name="L190"></a><tt class="py-lineno">190</tt>  <tt class="py-line">                <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L191"></a><tt class="py-lineno">191</tt>  <tt class="py-line">                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-13" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.wait
chimera.core.manager.Manager.wait" class="py-name" href="#" onclick="return doclink('link-13', 'wait', 'link-3');">wait</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L192"></a><tt class="py-lineno">192</tt>  <tt class="py-line">        <tt class="py-keyword">finally</tt><tt class="py-op">:</tt> </tt>
<a name="L193"></a><tt class="py-lineno">193</tt>  <tt class="py-line">            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-14" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.release
chimera.core.rwlock.ReadWriteLock.release" class="py-name" href="#" onclick="return doclink('link-14', 'release', 'link-5');">release</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
</div><a name="L194"></a><tt class="py-lineno">194</tt>  <tt class="py-line"> </tt>
<a name="ReadWriteLock.release"></a><div id="ReadWriteLock.release-def"><a name="L195"></a><tt class="py-lineno">195</tt> <a class="py-toggle" href="#" id="ReadWriteLock.release-toggle" onclick="return toggle('ReadWriteLock.release');">-</a><tt class="py-line">    <tt class="py-keyword">def</tt> <a class="py-def-name" href="chimera.core.rwlock.ReadWriteLock-class.html#release">release</a><tt class="py-op">(</tt><tt class="py-param">self</tt><tt class="py-op">)</tt><tt class="py-op">:</tt> </tt>
</div><div id="ReadWriteLock.release-collapsed" style="display:none;" pad="+++" indent="++++++++"></div><div id="ReadWriteLock.release-expanded"><a name="L196"></a><tt class="py-lineno">196</tt>  <tt class="py-line">        <tt class="py-docstring">"""Release the currently held lock.</tt> </tt>
<a name="L197"></a><tt class="py-lineno">197</tt>  <tt class="py-line"><tt class="py-docstring"></tt> </tt>
<a name="L198"></a><tt class="py-lineno">198</tt>  <tt class="py-line"><tt class="py-docstring">        In case the current thread holds no lock, a ValueError is thrown."""</tt> </tt>
<a name="L199"></a><tt class="py-lineno">199</tt>  <tt class="py-line"> </tt>
<a name="L200"></a><tt class="py-lineno">200</tt>  <tt class="py-line">        <tt class="py-name">me</tt> <tt class="py-op">=</tt> <tt class="py-name">currentThread</tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L201"></a><tt class="py-lineno">201</tt>  <tt class="py-line">        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-15" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.acquire" class="py-name" href="#" onclick="return doclink('link-15', 'acquire', 'link-0');">acquire</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L202"></a><tt class="py-lineno">202</tt>  <tt class="py-line">        <tt class="py-keyword">try</tt><tt class="py-op">:</tt> </tt>
<a name="L203"></a><tt class="py-lineno">203</tt>  <tt class="py-line">            <tt class="py-keyword">if</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-keyword">is</tt> <tt class="py-name">me</tt><tt class="py-op">:</tt> </tt>
<a name="L204"></a><tt class="py-lineno">204</tt>  <tt class="py-line">                <tt class="py-comment"># We are the writer, take one nesting depth away.</tt> </tt>
<a name="L205"></a><tt class="py-lineno">205</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt> <tt class="py-op">-=</tt> <tt class="py-number">1</tt> </tt>
<a name="L206"></a><tt class="py-lineno">206</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-keyword">not</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writercount</tt><tt class="py-op">:</tt> </tt>
<a name="L207"></a><tt class="py-lineno">207</tt>  <tt class="py-line">                    <tt class="py-comment"># No more write locks; take our writer position away and</tt> </tt>
<a name="L208"></a><tt class="py-lineno">208</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-comment"># notify waiters of the new circumstances.</tt> </tt>
<a name="L209"></a><tt class="py-lineno">209</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__writer</tt> <tt class="py-op">=</tt> <tt class="py-name">None</tt> </tt>
<a name="L210"></a><tt class="py-lineno">210</tt>  <tt class="py-line">                    <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-16" class="py-name" targets="Method chimera.core.chimeraobject.ChimeraObject.notifyAll()=chimera.core.chimeraobject.ChimeraObject-class.html#notifyAll"><a title="chimera.core.chimeraobject.ChimeraObject.notifyAll" class="py-name" href="#" onclick="return doclink('link-16', 'notifyAll', 'link-16');">notifyAll</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L211"></a><tt class="py-lineno">211</tt>  <tt class="py-line">            <tt class="py-keyword">elif</tt> <tt class="py-name">me</tt> <tt class="py-keyword">in</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">:</tt> </tt>
<a name="L212"></a><tt class="py-lineno">212</tt>  <tt class="py-line">                <tt class="py-comment"># We are a reader currently, take one nesting depth away.</tt> </tt>
<a name="L213"></a><tt class="py-lineno">213</tt>  <tt class="py-line"><tt class="py-comment"></tt>                <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt> <tt class="py-op">-=</tt> <tt class="py-number">1</tt> </tt>
<a name="L214"></a><tt class="py-lineno">214</tt>  <tt class="py-line">                <tt class="py-keyword">if</tt> <tt class="py-keyword">not</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt><tt class="py-op">:</tt> </tt>
<a name="L215"></a><tt class="py-lineno">215</tt>  <tt class="py-line">                    <tt class="py-comment"># No more read locks, take our reader position away.</tt> </tt>
<a name="L216"></a><tt class="py-lineno">216</tt>  <tt class="py-line"><tt class="py-comment"></tt>                    <tt class="py-keyword">del</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">[</tt><tt class="py-name">me</tt><tt class="py-op">]</tt> </tt>
<a name="L217"></a><tt class="py-lineno">217</tt>  <tt class="py-line">                    <tt class="py-keyword">if</tt> <tt class="py-keyword">not</tt> <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__readers</tt><tt class="py-op">:</tt> </tt>
<a name="L218"></a><tt class="py-lineno">218</tt>  <tt class="py-line">                        <tt class="py-comment"># No more readers, notify waiters of the new</tt> </tt>
<a name="L219"></a><tt class="py-lineno">219</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-comment"># circumstances.</tt> </tt>
<a name="L220"></a><tt class="py-lineno">220</tt>  <tt class="py-line"><tt class="py-comment"></tt>                        <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-17" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.notifyAll" class="py-name" href="#" onclick="return doclink('link-17', 'notifyAll', 'link-16');">notifyAll</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
<a name="L221"></a><tt class="py-lineno">221</tt>  <tt class="py-line">            <tt class="py-keyword">else</tt><tt class="py-op">:</tt> </tt>
<a name="L222"></a><tt class="py-lineno">222</tt>  <tt class="py-line">                <tt class="py-keyword">raise</tt> <tt class="py-name">ValueError</tt><tt class="py-op">(</tt><tt class="py-string">"Trying to release unheld lock"</tt><tt class="py-op">)</tt> </tt>
<a name="L223"></a><tt class="py-lineno">223</tt>  <tt class="py-line">        <tt class="py-keyword">finally</tt><tt class="py-op">:</tt> </tt>
<a name="L224"></a><tt class="py-lineno">224</tt>  <tt class="py-line">            <tt class="py-name">self</tt><tt class="py-op">.</tt><tt class="py-name">__condition</tt><tt class="py-op">.</tt><tt id="link-18" class="py-name"><a title="chimera.core.chimeraobject.ChimeraObject.release
chimera.core.rwlock.ReadWriteLock.release" class="py-name" href="#" onclick="return doclink('link-18', 'release', 'link-5');">release</a></tt><tt class="py-op">(</tt><tt class="py-op">)</tt> </tt>
</div></div><a name="L225"></a><tt class="py-lineno">225</tt>  <tt class="py-line"> </tt><script type="text/javascript">
<!--
expandto(location.href);
// -->
</script>
</pre>
<br />
<!-- ==================== NAVIGATION BAR ==================== -->
<table class="navbar" border="0" width="100%" cellpadding="0"
       bgcolor="#a0c0ff" cellspacing="0">
  <tr valign="middle">
  <!-- Home link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="chimera-module.html">Home</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Tree link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="module-tree.html">Trees</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Index link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="identifier-index.html">Indices</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Help link -->
      <th>&nbsp;&nbsp;&nbsp;<a
        href="help.html">Help</a>&nbsp;&nbsp;&nbsp;</th>

  <!-- Project homepage -->
      <th class="navbar" align="right" width="100%">
        <table border="0" cellpadding="0" cellspacing="0">
          <tr><th class="navbar" align="center"
            ><a class="navbar" target="_top" href="http://chimera.ufsc.br/">Chimera - Observatoty Automation System</a></th>
          </tr></table></th>
  </tr>
</table>
<table border="0" cellpadding="0" cellspacing="0" width="100%%">
  <tr>
    <td align="left" class="footer">
    <a href="epydoc-log.html">Generated by Epydoc
    3.0beta1 on Sat Feb  7 18:37:00 2009</a>
    </td>
    <td align="right" class="footer">
      <a href="http://epydoc.sourceforge.net">http://epydoc.sourceforge.net</a>
    </td>
  </tr>
</table>

<script type="text/javascript">
  <!--
  // Private objects are initially displayed (because if
  // javascript is turned off then we want them to be
  // visible); but by default, we want to hide them.  So hide
  // them unless we have a cookie that says to show them.
  checkCookie()
  // -->
</script>
  
</body>
</html>
